An integrated circuit (“IC”) is a device (e.g., a semiconductor device) or electronic system that includes many electronic components, such as transistors, resistors, diodes, etc. These components are often interconnected to form multiple circuit components, such as gates, cells, memory units, arithmetic units, controllers, decoders, etc. An IC includes multiple layers of wiring that interconnect the IC's electronic and circuit components.
Design engineers design ICs by transforming logical or circuit descriptions of the ICs' components into geometric descriptions, called design layouts. IC design layouts typically include (1) circuit modules (i.e., geometric representations of electronic or circuit IC components) with pins and (2) interconnect lines (i.e., geometric representations of wiring) that connect the pins of the circuit modules. In this fashion, design layouts often describe the behavioral, architectural, functional, and structural attributes of the IC. To create the design layouts, design engineers typically use electronic design automation (“EDA”) applications. These applications provide sets of computer-based tools for creating, editing, analyzing, and verifying design layouts. The applications also render the layouts on a display device or to a storage for displaying later.
Fabrication foundries (“fabs”) manufacture ICs based on the design layouts using a photolithographic process. Photolithography is an optical printing and fabrication process by which patterns on a photolithographic mask (i.e., “photomask,” or “mask”) are imaged and defined onto a photosensitive layer coating a substrate. To fabricate an IC, photomasks are created using the IC design layout as a template. The photomasks contain the various geometries (i.e., features) of the IC design layout. The various geometries contained on the photomasks correspond to the various base physical IC elements that comprise functional circuit components such as transistors, interconnect wiring, via pads, as well as other elements that are not functional circuit elements but are used to facilitate, enhance, or track various manufacturing processes.
Before the design layouts are released to fabs, the design layouts are verified against a set of design constraints or rules (e.g., a design constraint that requires a minimum distance between two geometries in a design layout) imposed on the various geometries of the IC design layouts. By abiding the design constraints, the design engineers ensure that the ICs manufactured based on the design layouts would function properly. To aid the design engineers in verifying the design layouts, some EDA applications provide design violation markers. Each of the violation markers indicates that a set of geometries of the IC design layout does not meet a design constraint or rule. These markers are in form of data and can be rendered on a display device along with the design layouts to provide visual cues for the engineers to spot and address any design rule violations.